gnuplot + ftlk: fill_01_1, fill_02_1: hidden edges keep visible in ML, not with fltk or gnuplot. This seems to be a ML bug when printing to PNG or JPEG and works (same output like gnuplot+fltk) when printing to ps. In FLTK the on-screen images shows the hidden edge and becomes invisible when printing.

gnuplot + fltk: hold_07_1: red rectangle hides the '^' plot markers. In ML they disappear on-screen as soon as xlim is changed or zoomed. Is this a ML bug? What is the prefered behaviour?

gnuplot + fltk patch_04_1: the demo incorrectly assumes the patch "facecolor" is "flat" as octave currently sets this by default (whereas in matlab "facecolor" is "none" by default). This should be fixed with bug#42159 (this probably is also the cause for black faces in shrinkfaces*)

gnuplot only differences

There are a lot of gnuplot differences and it might be nice to fix those, but someone would have to take an interest. Octave is moving towards OpenGL for all plotting so most developers focuses on
bug fixes for that toolkit.

Nevertheless here are some visual gnuplot ONLY problems which need some attention:

won't fix or Octave only feature

fltk/ML axis_09, axis_10, axis_11, axis_12, axis_13: No, [x,y]axislocation' 'zero' (http://savannah.gnu.org/bugs/?40588). This is an Octave (and gnuplot) only feature. We can either blacklist, or visually skip over the comparison since it is blank for Matlab. Perhaps should be removed from demos or blacklist axis_09 in dump.m script

matlab comet3_01_1, comet_01_1.png: Only the beginning of the animation is printed. Matlab implements comet in a completely different way which means printing isn't really possible for them.